Screenshot of X running on Gloire

There’s No Rust On This Ironclad Kernel

November 12, 2025 by No comments

Rust is the new hotness in programming languages because of how solid its memory protections are. Race conditions and memory leaks are hardly new issues however, and as greybeards are wont to point out, they were kind of a solved problem already: we have Ada. So if you want a memory-protected kernel but aren’t interested in the new kids’ rusty code, you might be interested in the Ironclad OS kernel, written entirely in Ada.

OK, not entirely in classic Ada– they claim to use SPARK, too, but since SPARK and Ada converged syntax-wise over a decade ago, we’re just going to call it Ada. The SPARK toolchain means they can get this kernel “formally-verified” however, which is a big selling point. If you’re not into CS, that just means the compiler can confirm the code is going to do what we want under all possible conditions — which is a nice thing to be able to say about the heart of your operating system, I think we can all agree. It’s a nice thing to be able to say about any code, which is one reason why you might want to be programming in Ada.

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Cheap Multimeter Gets Webified

November 12, 2025 by 2 Comments

[Mellow Labs] wanted to grab a multimeter that could do Bluetooth. Those are cheap and plentiful, but the Bluetooth software was, unsurprisingly, somewhat lacking. A teardown shows a stock Bluetooth module. A quick search found a GitHub with software. But then he had a fiendish idea: could you replace the Bluetooth module with an ESP32 and use WiFi instead of Bluetooth?

This was as good an excuse as any to buy a cheap logic analyzer. Armed with some logic captures, it was easy to figure out how to fake the meter into thinking a Bluetooth client was connected.

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2025 Component Abuse Challenge: Light An LED With Nothing

November 12, 2025 by 2 Comments

Should you spend some time around the less scientifically informed parts of the internet, it’s easy to find “Free power” stories. Usually they’re some form of perpetual motion machine flying in the face of the laws of conservation of energy, but that’s not to say that there is no free power.

The power just has to come from somewhere, and if you’re not paying for it there’s the bonus. [joekutz] has just such a project, lighting up LEDs with no power source or other active electronics.

Of course, he’s not discovered perpetual motion. Rather, while an LED normally requires a bit of current to light up properly, it seems many will produce a tiny amount of light on almost nothing. Ambient electromagnetic fields are enough, and it’s this effect that’s under investigation. Using a phone camera and a magnifier as a light detector he’s able to observe the feeble glow as the device is exposed to ambient fields.

In effect this is using the LED as the very simplest form of radio receiver, a crystal set with no headphone and only the leads, some wires, and high value resistors as an antenna. The LED is after all a diode, and it can thus perform as a rectifier. We like the demonstration even if we can’t quite see an application for it.

While we’re no longer taking new entries for the 2025 Component Abuse Challenge, we’ve still got plenty of creative hacks from the competition to show off. We’re currently tabulating the votes, and will announce the winners of this particularly lively challenge soon.

2025 Hackaday Component Abuse Challenge

FLOSS Weekly Episode 854: The Big Daddy Core

November 12, 2025 by No comments

This week Jonathan and Ben chat with Jason Shepherd about Ocre and Atym.io! That’s the lightweight WebAssembly VM that lets you run the same containers on Linux and a host of embedded platforms, on top of the Zephyr embedded OS. What was the spark that led to this project’s creation, what does Atym.io bring to the equation, and what are people actually doing with it? Watch to find out!

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Radio Apocalypse: Survivable Low-Frequency Communication System

November 12, 2025 by 4 Comments

In the global game of nuclear brinksmanship, secrets are the coin of the realm. This was especially true during the Cold War, when each side fielded armies of spies to ferret out what the other guy was up to, what their capabilities were, and how they planned to put them into action should the time come. Vast amounts of blood and treasure were expended, and as distasteful as the whole thing may be, at least it kept armageddon at bay.

But secrets sometimes work at cross-purposes to one’s goals, especially when one of those goals is deterrence. The whole idea behind mutually assured destruction, or MAD, was the certain knowledge that swift retaliation would follow any attempt at a nuclear first strike. That meant each side had to have confidence in the deadliness of the other’s capabilities, not only in terms of their warheads and their delivery platforms, but also in the systems that controlled and directed their use. One tiny gap in the systems used to transmit launch orders could spell the difference between atomic annihilation and at least the semblance of peace.

During the height of the Cold War, the aptly named Survivable Low-Frequency Communication System was a key part of the United States’ nuclear deterrence. Along with GWEN, HFGCS, and ERCS, SLFCS was part of the alphabet soup of radio systems designed to make sure the bombs got dropped, one way or another.

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Morse Code For China

November 12, 2025 by 29 Comments

It is well known that pictographic languages that use Hanzi, like Mandarin, are difficult to work with for computer input and output devices. After all, each character is a tiny picture that represents an entire word, not just a sound. But did you ever wonder how China used telegraphy? We’ll admit, we had not thought about that until we ran into [Julesy]’s video on the subject that you can watch below.

There are about 50,000 symbols, so having a bunch of dots and dashes wasn’t really practical. Even if you designed it, who could learn it? Turns out, like most languages, you only need about 10,000 words to communicate. A telegraph company in Denmark hired an astronomer who knew some Chinese and tasked him with developing the code. In a straightforward way, he decided to encode each word from a dictionary of up to 10,000 with a unique four-digit number.

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Pi Compute Modules Make For Compact Cluster

November 12, 2025 by 17 Comments

Raspberry Pi clusters have been a favorite project of homelabbers and distributed computing enthusiasts since the platform first launched over a decade ago, and for good reason. For an extremely low price this hardware makes it possible to experiment with parallel computing — something that otherwise isn’t easily accessible without lots of time, money, and hardware. This is even more true with the compute modules, as their size and cost makes some staggering builds possible like this cluster sporting 112 GB of RAM.

The project is based on the NanoCluster, a board that can hold seven compute modules in a form factor which, as [Christian] describes it, is about the size of a coffee mug. That means not only does it have a fairly staggering amount of RAM but also 28 processor cores to work with. Putting the hardware together is the easy part, though; [Christian] wanted to find the absolute easiest way of managing a system like this and decided on gitops, which is a method of maintaining a server where the desired system state is stored in Git, and automation continuously ensures the running environment on the hardware matches what’s in the repository.

For this cluster, it means that the nodes themselves can be swapped in and out, with new nodes automatically receiving instructions and then configuring themselves automatically. Updates and changes made on Git are pushed to the nodes automatically as well and there’s not much that needs to be done manually at all. In much the same way that immutable Linux distributions move all of the hassle of administering a system to something like a config file, tools like gitops do the same for servers and clusters like this, and it’s worth checking out [Christian]’s project to get an idea of just how straightforward it can be now.